Articles studying natural history and prognostic factors can be retrospective case series

Diagnostic case control studies will be excluded

Appears in a peer-reviewed publication

Has 10 or more patients per group

Is of humans

Is published in English

Is published in or after 1966

Reports results quantitatively

Has follow up of at least two years except for when healing or adverse events are the outcome

Has ≥50% patient follow-up (if the follow-up is >50% but <80%, the study quality will be downgraded)

Is not an in vitro study

Is not a biomechanical study

Is not performed on cadavers

Inclusion of Studies with Mixed Patient Populations

The work group specified a priori to the literature search that the studies must enroll and report the results of patients with osteochondritis dissecans of the knee. Studies with mixed populations must report the results of patients with osteochondritis dissecans of the knee separately or if the results are combined, 80% of the patient population must be of patients with osteochondritis dissecans of the knee in order to consider the study for inclusion in this guideline.

Best Available Evidence

When examining primary studies, the work group analyzed the best available evidence regardless of study design. They first considered the randomized controlled trials (RCTs) identified by the search strategy. In the absence of two or more RCTs, the work group sequentially searched for prospective controlled trials, prospective comparative studies, retrospective comparative studies, and prospective case-series studies. Only studies of the highest level of available evidence were included, assuming that there were 2 or more studies of that higher level. For example, if there were two Level II studies that addressed the recommendation, Level III and IV studies were not included.

Literature Searches

The work group attempted to make the searches for articles comprehensive. Using comprehensive literature searches ensures that the evidence they considered for this guideline is not biased for (or against) any particular point of view.

The work group searched for articles published from January 1966 to March 24, 2010. Four electronic databases were searched: PubMed, EMBASE, CINAHL, and The Cochrane Central Register of Controlled Trials. Strategies for searching electronic databases were constructed by a medical librarian using previously published search strategies to identify relevant studies.

Searches of electronic databases were supplemented with manual screening of the bibliographies of all retrieved publications. The bibliographies of recent systematic reviews and other review articles were also searched for potentially relevant citations. Finally, work group members provided a list of potentially relevant studies that were not identified by the searches. All articles identified were subject to the study selection criteria listed above.

The work group did not include systematic reviews compiled by others or guidelines developed by other organizations. These documents are developed using different inclusion criteria than those specified by the American Academy of Orthopaedic Surgeons (AAOS) work group. Therefore they may include studies that do not meet AAOS inclusion criteria. These documents were recalled, if the abstract suggested they might provide an answer to one of the recommendations, and their bibliographies were searched for additional studies to supplement the systematic review.

The study attrition diagram in Appendix III of the original guideline provides details about the inclusion and exclusion of the studies considered for this guideline. The search strategies used to identify these studies are provided in Appendix IV of the original guideline.

Number of Source Documents

16 articles were included

Methods Used to Assess the Quality and Strength of the Evidence

Weighting According to a Rating Scheme (Scheme Given)

Rating Scheme for the Strength of the Evidence

Levels of Evidence for Primary Research Question1

Types of Studies

Therapeutic Studies
Investigating the results of treatment

Prognostic Studies
Investigating the effects of a patient characteristic on the outcome of disease

Diagnostic Studies
Investigating a diagnostic test

Economic and Decision Analyses
Developing an economic or decision model

1 A complete assessment of quality of individual studies requires critical appraisal of all aspects of the study design.2 A combination of results from two or more prior studies.3 Studies provided consistent results.4 Study was started before the first patient enrolled.5 Patients treated one way (e.g., cemented hip arthroplasty) compared with a group of patients treated in another way (e.g., uncemented hip arthroplasty) at the same institution.6 The study was started after the first patient enrolled.7 Patients identified for the study based on their outcome, called "cases"; e.g., failed total hip arthroplasty, are compared to those who did not have outcome, called "controls"; e.g., successful total hip arthroplasty.8 Patients treated one way with no comparison group of patients treated in another way.

Methods Used to Analyze the Evidence

Meta-Analysis of Randomized Controlled TrialsReview of Published Meta-AnalysesSystematic Review with Evidence Tables

Description of the Methods Used to Analyze the Evidence

Data Extraction

Data elements extracted from studies were defined in consultation with the physician work group. The elements extracted are shown in Appendix V of the original guideline document. Evidence tables were constructed to summarize the best evidence pertaining to each preliminary recommendation. Disagreements about the accuracy of extracted data were resolved by consensus and consulting the work group. Disagreements were resolved by consensus and by consulting the physician work group.

The work group specified a priori to the literature search that data would be stratified by joint but that mixed studies could be accepted and reported as such. When studies did not separate the data by joint, it is not possible to report them separately. If a study with mixed joints reported the data for each joint, they were reported as such. If a study reported mixed joints but had less than 25 patients per joint, the analyst reported only the mixed data.

Judging the Quality of Evidence

Determining the quality of the included evidence is vitally important when preparing any evidence-based work product. Doing so conveys the amount of confidence one can have in any study's results. One has more confidence in high quality evidence than in low quality evidence.

Assigning a level of evidence on the basis of study design plus other quality characteristics ties the levels of evidence reported more closely to quality than levels of evidence based only on study design. Because the work group ties quality to levels of evidence, they are able to characterize the confidence one can have in their results. Accordingly, they characterize the confidence one can have in Level I evidence as high, the confidence one can have in Level II and III evidence as moderate, and the confidence one can have in Level IV and V evidence as low. Similarly, throughout the guideline they refer to Level I evidence as reliable, Level II and III evidence as moderately reliable, and Level IV and V evidence as not reliable.

Diagnostic Studies

In studies investigating a diagnostic test, the work group used the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) instrument (Appendix VI in the original guideline document) to identify potential bias and assess variability and the quality of reporting in studies reporting the effectiveness of diagnostic techniques. Studies without any indication of bias are categorized as high quality studies. The quality of a study that has bias in the study design (disease progression, partial verification), index test description, or clinical data was lowered for each bias present. Quality could be further downgraded if greater than 50% of the QUADAS (at least 3 of the 5) questions that assess the quality of reporting determined there was important information missing. Studies that have bias known to affect measures of diagnostic accuracy (i.e., spectrum bias, incorporation bias) were considered very low quality and not considered for analysis.

Treatment Studies

In studies investigating the result of treatment, the work group assessed the quality of the evidence for each outcome at each time point reported in a study. They did not simply assess the overall quality of a study. This approach follows the recommendations of the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) working group as well as others.

Quality was evaluated on a per outcome basis rather than a per study basis because quality is not necessarily the same for all outcomes and all follow-up times reported in a study. For example, a study might report results immediately after patients received a given treatment and after some period of time has passed. Often, nearly all enrolled patients contribute data at early follow-up times but, at much later follow-up times, only a few patients may contribute data. One has more confidence in the earlier data than in the later data. The fact that a higher quality score would be assigned to the earlier results reflects this difference in confidence.

The work group assessed the quality of treatment studies using a two step process. First, they assigned quality to all results reported in a study based solely on that study's design. Accordingly, all data presented in randomized controlled trials were initially categorized as high quality evidence, all results presented in non-randomized controlled trials and other prospective comparative studies were initially categorized as moderate quality, all results presented in retrospective comparative and case-control studies were initially categorized as low quality, and all results presented in prospective case-series reports were initially categorized as low quality. The work group next assessed each outcome at each reported time point using a quality questionnaire and, when quality standards were not met, downgraded the level of evidence (for this outcome at this time point) by one level (see Appendix VI in the original guideline document).

Prognostic Studies

In studies investigating the effect of a characteristic on the outcome of disease, quality was assessed using a two step process including a quality questionnaire (Appendix VI in the original guideline document). The quality questionnaire was developed from previously published literature addressing the use and analysis of prognostic variables. All studies were initially assigned as high quality and when quality standards were not met, as determined by the quality questionnaire, the study quality was lowered. The lowering of study quality was cumulative. Studies with five or more flaws indicated by the quality questionnaire were reduced to very low quality and not considered in our analysis.

Statistical Methods

Likelihood ratios, sensitivity, specificity, and 95% confidence intervals were calculated to determine the accuracy of diagnostic modalities based on two by two diagnostic contingency tables extracted from the included studies. When summary values of sensitivity, specificity, or other diagnostic performance measures were reported, estimates of the diagnostic contingency table were used to calculate likelihood ratios.

Likelihood ratios (LR) indicate the magnitude of the change in probability of disease due to a given test result. For example, a positive likelihood ratio of 10 indicates that a positive test result is 10 times more common in patients with disease than in patients without disease. Likelihood ratios are interpreted according to previously published values, as seen in Table 3 of the original guideline document.

Methods Used to Formulate the Recommendations

Expert Consensus (Nominal Group Technique)

Description of Methods Used to Formulate the Recommendations

This guideline and systematic review were prepared by The Diagnosis and Treatment of Osteochondritis Dissecans of the Knee guideline work group with the assistance of the American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guidelines Unit in the Department of Research and Scientific Affairs at the AAOS (see Appendix I in the original guideline document).

To develop this guideline, the work group held an introductory meeting to develop the scope of the guideline on April 19, 2009. Upon completion of the systematic review, the work group met again on April 10 and 11, 2010 to write and vote on the final recommendations and associated rationales for each recommendation based on the evidence.

Formulating Preliminary Recommendations

The work group began work on this guideline by constructing a set of preliminary recommendations. These recommendations specify [what] should be done in [whom], [when], [where], and [how often or how long]. They function as questions for the systematic review, not as final recommendations or conclusions. Preliminary recommendations are almost always modified on the basis of the results of the systematic review. Once established, these a priori preliminary recommendations cannot be modified until the final work group meeting, they must be addressed by the systematic review, and the relevant review results must be presented in the final guideline.

Defining the Strength of the Recommendations

Judging the quality of evidence is only a stepping stone towards arriving at the strength of a guideline recommendation. Unlike Levels of Evidence (which apply only to a given result at a given follow-up time in a given study) strength of recommendation takes into account the quality, quantity, and applicability of the available evidence. Strength also takes into account the trade-off between the benefits and harms of a treatment or diagnostic procedure, and the magnitude of a treatment's effect.

Strength of recommendation expresses the degree of confidence one can have in a recommendation. As such, the strength expresses how possible it is that a recommendation will be overturned by future evidence. It is very difficult for future evidence to overturn a recommendation that is based on many high quality randomized controlled trials that show a large effect. It is much more likely that future evidence will overturn recommendations derived from a few small case series. Consequently, recommendations based on the former kind of evidence are given a high strength of recommendation and recommendations based on the latter kind of evidence are given a low strength.

To develop the strength of a recommendation, AAOS staff first assigned a preliminary strength for each recommendation that took only the quality and quantity of the available evidence into account (see "Rating Scheme for the Strength of the Recommendations" field). Work group members then modified the preliminary strength using the "Form for Assigning Strength of Recommendation (Interventions)" shown in Appendix VII of the original guideline document.

Consensus Development

The recommendations and their strength were voted on using a structured voting technique known as the nominal group technique. Details of this technique are presented in Appendix VIII of the original guideline document. Voting on guideline recommendations was conducted using a secret ballot and work group members were blinded to the responses of other members. If disagreement between work group members was significant, there was further discussion to see whether the disagreement(s) could be resolved. Up to three rounds of voting were held to attempt to resolve disagreements. If disagreements were not resolved following three voting rounds, no recommendation was adopted. Lack of agreement is a reason that the strength for some recommendations is labeled "Inconclusive."

Rating Scheme for the Strength of the Recommendations

To develop the strength of a recommendation, American Academy of Orthopaedic Surgeons (AAOS) staff first assigned a preliminary strength for each recommendation that took only the quality and quantity of the available evidence into account (see table below). Work group members then modified the preliminary strength using the "Form for Assigning Strength of Recommendation (Interventions)" shown in Appendix VII of the original guideline document.

Strength of Recommendation

Guideline Language

Strength of Recommendation

Description of Evidence

The work group recommends

Strong

Level I evidence from more than one study with consistent findings for recommending for or against the intervention or diagnostic.

The work group suggests

Moderate

Level II or III evidence from more than one study with consistent findings, or Level I evidence from a single study for recommending for or against the intervention or diagnostic.

Treatment X is an option

Weak

Level IV or V evidence from more than one study with consistent findings, or Level II or III evidence from a single study for recommending for or against the intervention or diagnostic.

The work group is unable to recommend for or against Treatment X

Inconclusive

The evidence is insufficient or conflicting and does not allow a recommendation for or against the intervention or diagnostic.

In the absence of reliable evidence, it is the opinion of the work group…*

Consensus*

There is no supporting evidence. In the absence of reliable evidence, the work group is making a recommendation based on their clinical opinion considering the known harms and benefits associated with the treatment.

*Consensus based recommendations are made according to specific criteria. These criteria can be found in Appendix VI of the original guideline document.

Cost Analysis

A formal cost analysis was not performed and published cost analyses were not reviewed.

Method of Guideline Validation

External Peer ReviewInternal Peer Review

Description of Method of Guideline Validation

Peer Review

The draft of the guideline and evidence report was peer reviewed by an expert, outside advisory panel that was nominated a priori by the physician work group prior to the development of the guideline. The physician members of the American Academy of Orthopaedic Surgeons (AAOS) Guidelines and Technology Oversight Committee, the Evidence Based Practice Committee, and the Occupational Health and Workers' Compensation Committee also provided peer review of the draft document. Peer review was accomplished using a structured peer review form (see Appendix IX in the original guideline document). The draft guideline was sent to a total of 11 reviewers and 6 returned reviews (see Appendix X in the original guideline). The disposition of all non-editorial peer review comments was documented and accompanied this guideline through the public commentary and the AAOS guideline approval process. The peer reviewer comments, the responses and the final guideline are posted to the AAOS website upon approval of the AAOS Board of Directors.

Public Commentary

After modifying the draft in response to peer review, the guideline was distributed for a thirty-day period of "Public Commentary." Commentators consist of members of the AAOS Board of Directors (BOD), members of the Council on Research, Quality Assessment, and Technology (CORQAT), members of the Board of Councilors (BOC), and members of the Board of Specialty Societies (BOS). Based on these bodies, up to 185 commentators had the opportunity to provide input concerning the content of this guideline and the AAOS guideline development process. Of these, 2 returned public comments.

The AAOS Guideline Approval Process

Following public commentary, the work group and clinical practice guidelines unit edited the draft if public comments indicated changes were necessary based on the evidence. This final guideline draft, peer review comments and the responses as well as a summary of all changes made during the review process were then forwarded into the approval process. The guideline draft was sequentially approved by the AAOS Guidelines Oversight Committee, the AAOS Evidence-Based Practice Committee, the AAOS Council on Research, Quality Assessment, and Technology, and the AAOS Board of Directors. Descriptions of these bodies are provided in Appendix II of the original guideline document. No changes to the draft may occur during the approval process; all entities vote to approve or reject the document.

Recommendations

Major Recommendations

Definitions of the strength of recommendations (Strong, Moderate, Weak, Inconclusive, and Consensus) are provided at the end of the "Major Recommendations" field.

Note from the American Academy of Orthopaedic Surgeons (AAOS): The following is a summary of the recommendations in the AAOS clinical practice guideline, The Diagnosis and Treatment of Osteochondritis Dissecans (OCD) of the Knee. The scope of this guideline is specifically limited to osteochondritis dissecans of the knee. This summary does not contain rationales that explain how and why these recommendations were developed nor does it contain the evidence supporting these recommendations. All readers of this summary are strongly urged to consult the full guideline and evidence report for this information. The work group is confident that those who read the full guideline and evidence report will also see that the recommendations were developed using systematic evidence-based processes designed to combat bias, enhance transparency, and promote reproducibility. This summary of recommendations is not intended to stand alone. Treatment decisions should be made in light of all circumstances presented by the patient. Treatments and procedures applicable to the individual patient rely on mutual communication between patient, physician and other healthcare practitioners.

The work group is unable to recommend for or against x-rays on the contralateral asymptomatic knee in patients with confirmed OCD of one knee.

Strength of Recommendation: Inconclusive

In a patient with a known OCD lesion on x-ray, a magnetic resonance imaging (MRI) of the knee is an option to characterize the OCD lesion or when concomitant knee pathology is suspected such as meniscal pathology, anterior cruciate ligament (ACL) injury, or articular cartilage injury.

Strength of Recommendation: Weak

The work group is unable to recommend for or against non-operative treatment (casting, bracing, splinting, unloader brace, electrical or ultrasound bone stimulators, or activity restriction alone) for asymptomatic skeletally immature patients with OCD.

Strength of Recommendation: Inconclusive

The work group is unable to recommend for or against a specific non-operative treatment (casting, bracing, splinting, unloader brace, electrical or ultrasound bone stimulators, or activity restriction alone) for symptomatic skeletally immature patients with OCD.

Strength of Recommendation: Inconclusive

The work group is unable to recommend for or against arthroscopic drilling in symptomatic skeletally immature patients with a stable lesion(s) who have failed to heal with non operative treatment for at least three months.

Strength of Recommendation: Inconclusive

In the absence of reliable evidence, it is the opinion of the work group that symptomatic skeletally immature patients with salvageable unstable or displaced OCD lesions be offered the option of surgery.

Strength of Recommendation: Consensus

The work group is unable to recommend for or against a specific cartilage repair technique in symptomatic skeletally immature patients with unsalvageable fragment.

Strength of Recommendation: Inconclusive

The work group is unable to recommend for or against repeat MRI for asymptomatic skeletally mature patients.

Strength of Recommendation: Inconclusive

The work group is unable to recommend for or against treating asymptomatic skeletally mature patients with OCD progression (as identified by X-ray or MRI) like symptomatic patients.

Strength of Recommendation: Inconclusive

In the absence of reliable evidence, it is the opinion of the work group that symptomatic skeletally mature patients with salvageable unstable or displaced OCD lesions be offered the option of surgery.

Strength of Recommendation: Consensus

The work group is unable to recommend for or against a specific cartilage repair technique in symptomatic skeletally mature patients with an unsalvageable OCD lesions.

Strength of Recommendation: Inconclusive

In the absence of reliable evidence, it is the opinion of the work group that patients who remain symptomatic after treatment for OCD have a history and physical examination, x-rays and/or MRI to assess healing.

Strength of Recommendation: Consensus

The work group is unable to recommend for or against physical therapy for patients with OCD treated non-operatively.

Strength of Recommendation: Inconclusive

In the absence of reliable evidence, it is the opinion of the work group that patients who have received surgical treatment of OCD be offered post-operative physical therapy.

Strength of Recommendation: Consensus

The work group is unable to recommend for or against counseling patients about whether activity modification and weight control prevents onset and progression of OCD to osteoarthritis (osteoarthrosis).

Strength of Recommendation: Inconclusive

Definitions:

Levels of Evidence: See the "Rating Scheme for the Strength of the Evidence" field.

Strength of Recommendation

Guideline Language

Strength of Recommendation

Description of Evidence

The work group recommends

Strong

Level I evidence from more than one study with consistent findings for recommending for or against the intervention or diagnostic.

The work group suggests

Moderate

Level II or III evidence from more than one study with consistent findings, or Level I evidence from a single study for recommending for or against the intervention or diagnostic.

Treatment X is an option

Weak

Level IV or V evidence from more than one study with consistent findings, or Level II or III evidence from a single study for recommending for or against the intervention or diagnostic.

The work group is unable to recommend for or against Treatment X

Inconclusive

The evidence is insufficient or conflicting and does not allow a recommendation for or against the intervention or diagnostic.

In the absence of reliable evidence, it is the opinion of the work group…*

Consensus*

There is no supporting evidence. In the absence of reliable evidence, the work group is making a recommendation based on their clinical opinion considering the known harms and benefits associated with the treatment.

*Consensus based recommendations are made according to specific criteria. These criteria can be found in Appendix VI of the original guideline document.

Benefits/Harms of Implementing the Guideline Recommendations

Surgical treatments are associated with some known risks such as infection, bleeding, venous thromboembolic events and persistent pain, although arthroscopic approaches have relatively low risk compared to more invasive surgeries.

Contraindications

Contraindications

Contraindications vary widely based on the treatment administered. Therefore, discussion of available treatments and procedures applicable to the individual patient rely on mutual communication between the patient and physician, weighing the potential risks and benefits for that patient.

Qualifying Statements

Qualifying Statements

An American Academy of Orthopaedic Surgeons (AAOS) physician volunteer Work Group developed this clinical practice guideline based on a systematic review of the current scientific and clinical information as well as accepted approaches to treatment and/or diagnosis. This clinical practice guideline is not intended to be used as a fixed protocol, as some patients may require more or less treatment or different means of diagnosis. Clinical patients may not necessarily be the same as those found in a clinical trial. Patient care and treatment should always be based on a clinician's independent medical judgment, given the individual patient's clinical circumstances.

Some drugs or medical devices referenced or described in this clinical practice guideline may not have been cleared by the Food and Drug Administration (FDA) or may have been cleared for a specific use only. The FDA has stated that it is the responsibility of the physician to determine the FDA clearance status of each drug or device he or she wishes to use in clinical practice.

This summary of recommendations is not intended to stand alone. Treatment decisions should be made in light of all circumstances presented by the patient. Treatments and procedures applicable to the individual patient rely on mutual communication between patient, physician and other healthcare practitioners.

This guideline should not be construed as including all proper methods of care or excluding methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment must be made in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution.

Shorter versions of the guideline are available in other venues. Publication of most guidelines is announced by an Academy press release, articles authored by the work group and published in the Journal of the American Academy of Orthopaedic Surgeons, and articles published in AAOS Now. Most guidelines are also distributed at the AAOS Annual Meeting in various venues such as on Academy Row and at Committee Scientific Exhibits.

Selected guidelines are disseminated by webinar, an Online Module for the Orthopaedic Knowledge Online website, Radio Media Tours, Media Briefings, and by distributing them at relevant Continuing Medical Education (CME) courses and at the AAOS Resource Center.

Other dissemination efforts outside of the AAOS will include submitting the guideline to the National Guideline Clearinghouse and distributing the guideline at other medical specialty societies' meetings.

Implementation Tools

Quick Reference Guides/Physician Guides

For information about availability, see the Availability of Companion Documents and Patient Resources fields below.

In accordance with American Academy of Orthopaedic Surgeons (AAOS) policy, all individuals whose names appear as authors or contributors to this clinical practice guideline filed a disclosure statement as part of the submission process. All panel members provided full disclosure of potential conflicts of interest prior to voting on the recommendations contained within this clinical practice guideline.

All members of the AAOS work group disclosed any conflicts of interest prior to the development of the recommendations for this guideline. Conflicts of interest are disclosed in writing with the American Academy of Orthopaedic Surgeons via a private on-line reporting database and also verbally at the recommendation approval meeting.

Disclosure Items Answered: (n) = Respondent answered 'No' to all items indicating no conflicts. 1 = Royalties from a company or supplier; 2 = Speakers bureau/paid presentations for a company or supplier; 3A = Paid employee for a company or supplier; 3B = Paid consultant for a company or supplier; 3C = Unpaid consultant for a company or supplier; 4 = Stock or stock options in a company or supplier; 5 = Research support from a company or supplier as a PI; 6 = Other financial or material support from a company or supplier; 7 = Royalties, financial or material support from publishers; 8 = Medical/orthopaedic publications editorial/governing board; 9 = Board member/committee appointments for a society.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions. For more information, please contact AAOS Department of Research and Scientific Affairs, 6300 North River Road, Rosemont, IL 60018; Phone: (847) 823-7186; Fax: (847) 823-8125.

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